Salivary Gland Cancer

Determining the Stage of the Cancer

The final step before discussing treatment options is a determination of the stage of the cancer. As with all cancers of the head and neck, doctors in the U.S. use the AJCC Cancer Staging Manual (7th Ed) to determine the stage based on three factors.

Factors that go into determining the stage of the cancer

T

Characteristics of the main tumor mass

N

Status of the lymph nodes in the neck (i.e. evidence of cancer spread)

M

Status of cancer spread to parts of the body outside of the head and neck

At first, you will be given a clinical stage based on all of the available information.

Clinical staging (cTNM) is determined from any information your doctor might have about how extensive the cancer is BEFORE starting any treatment. Stage is determined based on your doctor’s physical exam, imaging studies, laboratory work and biopsies. Classification of clinical stage is described using the lower case prefix c (e.g. cT, cN, cM).

If there is surgical removal of the cancer as part of your treatment, a pathologist will analyze the tumor and any lymph nodes that may have been removed. You will then be assigned a pathologic stage.

Pathologic staging (pTNM) provides more data. Classification of pathology stage is described using the lower case prefix p (e.g. pT, pN, pM). This may or may not differ from the clinical stage.

There are also a number of other lower-case prefixes that might be used in the staging of your cancer.

The subscript y (yTNM) is used to assign a cancer stage after some sort of medical, systemic or radiation treatment is given (posttherapy or Postneoadjuvant stage). It is typically combined with either a clinical or pathologic stage. For example, ycT2N0M0 indicates that after some sort of non-surgical therapy, the new clinical stage is T2N0M0.

The subscript r (rTNM) is used when the tumor has recurred after some period of time in which it was gone. This is called Retreatment Classification Stage. Your doctor will use all the available information to assign you a retreatment stage.

Note that minor salivary gland cancers fall into the staging system based on where they are located. This means that if you have a minor salivary gland cancer on the roof of your mouth (palate), your TNM and Overall Stage will be based on the rules in the oral cavity cancersection.

T Stage: The Main Tumor Mass

Based on a physical examination and review of any imaging, your doctor should be able to give you a T stage that falls within one of the following categories.

Tx

You know you have a salivary gland cancer but don’t know where the primary tumor is.

T0

There is no evidence of a primary tumor despite looking everywhere.

T1

The tumor is 2 centimeters or less in greatest dimension, and based on imaging and physical exam, it does not appear to be growing outside of the gland itself (such as into muscles or fat outside of the gland).

T2

The tumor is more than 2 centimeters but less than or equal to four centimeters in greatest dimension, and there is no obvious extension outside of the gland.

T3

Either the tumor is more than 4 centimeters in greatest dimension, OR the tumor is of any size but is clearly extending outside of the gland to structures around it.

T4a

This is moderately advanced disease. You’re in this stage if the tumor clearly invades into the skin, jawbone, ear canal or facial nerve (that is, the face doesn’t move properly).

T4b

This is very advanced disease. You’re in this stage if your tumor is invading into the skull base (bones below the brain) and/or pterygoid plates (bones deep in the middle of your head) and/or it encases the carotid artery (the main blood supply to one half or both sides of the brain).

N Stage: Spread of Cancer to the Lymph Nodes in the Neck

Next, your doctor will use all the available information and assign you an N stage. This is based on his or her assessment as to whether the cancer has spread to lymph nodes in the neck.

Nx

The neck lymph nodes cannot be assessed.

N0

There is no evidence of any spread to the nodes.

N1

There is a single node, on the same side of the main tumor, that is 3 centimeters or less in greatest size.

N2a

Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 centimeters but less than or equal to 6 centimeters in greatest dimension.

N2b

There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none of them are more than 6 centimeters in size.

N2c

There are lymph nodes in the neck on either the opposite side as the main cancer or on both sides of the neck, but none are more than 6 centimeters.

N3

There is spread to one or more neck lymph nodes, and the size is greater than 6 centimeters.

M Stage: Spread of Cancer Outside the Head and Neck

Finally, based on an assessment on the entire body, you will be assigned an M stage.

M0

No evidence of distant (outside the head and neck) spread.

M1

There is evidence of spread outside of the head and neck (i.e., in the lungs, bone, brain, etc.).

Your Cancer Stage

After TNM staging, your doctor can assign a cancer stage based on the following chart.

Stage I

TI

N0

M0

Stage II

T2

N0

M0

Stage III

T3

N0

M0

T1

N1

M0

T2

N1

M0

T3

N1

M0

Stage IVA

T4a

N0

M0

T4a

N1

M0

T1

N2

M0

T2

N2

M0

T3

N2

M0

T4a

N2

M0

Stage IVB

T4b

AnyN

M0

AnyT

N3

M0

Stage IVC

AnyT

AnyN

M1

Your Clinical Stage

Once the diagnostic tests are completed, before deciding what type of treatment you are going to receive, you should be given a clinical stage that will look similar to the example below.

CLINICAL STAGE

Example

Site

Major Salivary Gland

Subsite

Parotid

Type

Mucoepidermoid

Grade

Low grade

cT

cT2

cN

cN0

cM

cM0

cStage

cIII

* The lower-case subscript c indicates that this is a CLINICAL STAGE, the stage assigned based on all information available to your doctor before starting treatment.

After surgery, you should get a pathologic stagein regards to your tumor. It will look almost like the clinical stageyou received before starting treatment, but notice the “p” that indicates the stage group is based on an analysis of the entire tumor, with or without lymph nodes, under a microscope by a pathologist. In many cases, the pathologic stagewill be the same as the clinical stage, but sometimes it will change. You should consider the pathologic stage to bea more accurate assessment of your tumor at the time you start treatment.

After surgery, and after the pathologist has evaluated all of the tumor that was removed, you should be given a pathologic stagethat looks something like this:

PATHOLOGIC STAGE

Example

Site

Major Salivary Gland

Subsite

Parotid

Type

Mucoepidermoid

Grade

High grade

pT

pT3

pcN

pN0

pcM

pM0

pcStage

pIII

* The lower-case subscript p indicates that this is a PATHOLOGIC STAGE, the stage assigned after tumor removal and confirmation of cancer by a pathologist.